He said he wanted to do more to help countries such as Vietnam stop the illegal trade in rhino horn after talks with the Vietnamese prime minister, Nguyen Tan Dung.
At the same time the Foreign Office minister Grant Shapps called on all governments in Africa to end hunting such as the killing of the Zimbabwean lion. Shapps described the killing as revolting and said he had written to the Zimbabwean government to ask what more could be done to stop illegal hunting and poaching.
He described Cecil as “an icon of the wildlife world”.
Shapps wrote to the Zimbabwean environment minister, Oppah Muchinguri, saying: “I was distressed to read media reports about Cecil the lion being illegally killed by hunters in Zimbabwe earlier this month, as I am sure were you.
“It is clear that we share an ambition to secure the protection of threatened species, and in working towards an end to poaching and other illegal practices. I would welcome your thoughts on how we could work more closely together to help achieve our shared objectives on this issue.”
In Vietnam, Cameron was asked if Britain could do more to end the trophy imports that lie at the heart of the illegal wildlife trade, and he replied the government was playing a leading role in stopping trade in illegal wildlife.
Dung told Cameron rhinos in Vietnam had now been hunted to extinction in part due to the belief their horns had a medicinal quality.
Sold in shops in Hanoi, rhino bones imported from Africa are seen as a valuable commodity. Tiger bones are also valuable because tiger glue is highly prized by advocates of traditional medicine. It is said to to increase masculinity.
Cameron said he and Dung had discussed “how we could help the Vietnamese with this in terms of preventing this trade, which is leading to the loss of so many vital species. So we were actually discussing the issue of tiger bones, and rhino horn”.
Britain has promised £200,000 funding to the Vietnamese to stage a conference on the illegal wildlife trade next year.
This article was written by Patrick Wintour Political editor in Kuala Lumpur, for theguardian.com on Thursday 30th July 2015 12.04 Europe/Londonguardian.co.uk © Guardian News and Media Limited 2010